An example of a method for obtaining a two-dimensional spectral image is disclosed in Patent Document 1. In Patent Document 1, a multiband image is captured using a multiband camera including an object lens, a color filter array divided into a plurality of image capturing wavelength regions, a microlens array including a plurality of microlenses, and a two-dimensional detector for capturing an image for each spectrum divided by the color filter array.
Example 1 in Patent Document 1 illustrates a multiband camera in which the color filter array is disposed between the microlens array and the two-dimensional detector. Example 2 discloses a multiband camera in which the color filter array is disposed in the neighborhood of the object lens at a distance from the microlens array.